/Engine/Source/Runtime/SlateCore/Public/SlotBase.h
Remove the widget from its current slot. The removed widget is returned so that operations could be performed on it. If the null widget was being stored, an invalid shared ptr is returned instead.
const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > DetachWidget()